Оптимизация технического уровня индукционных электромеханических и статических преобразователей с вращающимся магнитным полем

Abstract

The thesis for granting the Degree of Candidate of Technical sciences in the specialty 05.09.01 – electrical machines and apparatus. – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2017. The thesis is devoted to questions of development of mathematical models of parameters of steady state and comparison of electromagnetic systems’ variants of squirrel-cage induction motors and transformers with a rotating magnetic field by criteria of weight, cost, active power losses, reactive power and generalized criteria, which has been obtained by the ideal point method. The method of objective functions with relative technical level indications and relative controlled variables has been used for solution of assigned tasks. In mathematical models of parameters of steady state of axial electromagnetic systems of mentioned converters the uneven radial distribution of magnetic induction in the magnetic circuit elements has been taken into account. For induction motors with internal and external rotors, and an axial magnetic flux, including sectioning of magnetic core, and transformers with a rotating magnetic field the optimum geometrical ratios have been determined. It has been shown, that an application of non-traditional variants of electromagnetic systems of induction converters could significantly improve indications of electrotechnical systems, for example the replacement of induction motors with an internal rotor on induction motors with an external rotor and an axial magnetic flux has been recommended, when the number of pole pairs was 1–3 and 3–4 respectively. Also ways to increase the starting torque of induction motors have been considered, and the method of determining efficiency and power factors of induction converters, depending on the controlled variables, has been developed.